In recent years, fuel injectors have largely replaced carburetors as a means for providing a controlled quantity of fuel to internal combustion engines. Fuel injected internal combustion engines have several advantages over carbureted engines:
(1) reduced hydrocarbon emissions;
(2) greater fuel economy due to improved fuel/air mixing and volumetric efficiency;
(3) elimination of combustion knock;
(4) elimination of carburetor icing; and
(5) more uniform distribution of fuel to engine cylinders.
However, fuel injectors presently available are relatively complex and expensive in comparison with carburetors. For example, fuel injectors commonly used on automotive gasoline engines require electronic control units, power supplies, and auxiliary fuel pumps. Because of their high cost and dependence on these components, fuel injectors have found widespread use only on engines designed for highway vehicles, aircraft, and other relatively expensive equipment. Thus far, it has not been economically feasible to equip smaller, lower horsepower equipment, such as garden tractors powered by two cycle gasoline engines, with fuel injectors. However, increasing concerns over air pollution will eventually require that even small, lower horsepower engines meet the strict hydrocarbon emissions standards presently applicable to the larger engines.
Consequently, a need exists for a simple, lightweight, low cost fuel injector for small internal combustion engines, particularly two cycle gasoline engines. Preferably, such a fuel injector will not require auxiliary electronic components, power supplies, fuel pumps, or other auxiliary equipment.